Steve Irwin Son Turns 13 ... What a Croc!

12/1/2016 7:31 AM PST BY TMZ STAFF

1201_robert_irwin_birthday_party_launch_3Steve Irwin's son, Robert, celebrated turning 13 by making his late dad proud -- cradling a baby crocodile and feeding others twice his size. 

Robert's party was at Australia Zoo with sister Bindi, mom Terri and a reptile-themed bday cake that looked like some kinda hatchling -- perhaps a T-Rex embryo? One-winged Pterodactyl?

Your guess is as good as ours, but the kid definitely partied like a croc star.